Fault-slip distribution characteristics and seismogenic tectonics of the M w 7.0 earthquake on 23 January 2024 in Wushi County, Xinjiang, revealed by InSAR

Abstract

Abstract Satellite data of the Sentinel-1 of a Mw7.0 earthquake on 23 January 2024, in Wushi County, Xinjiang, was used to obtain the interferometric synthetic aperture radar (InSAR) co-seismic deformation field by inverting the kinematic parameters of the seismogenic fault and the fine slip distribution characteristics. Finally, Coulomb stress characteristics and regional tectonic background research results were synthesised to assess the seismic hazard around the Kepingtage fold-and-thrust belt. The deformation field generated had a long axis-oriented NEE occurring in the Kepingtage fold-and-thrust belt. The line-of-sight uplift deformation promoted the uplift of the Kepingtage fold-and-thrust belt. The seismogenic fault was assumed to be the Maidan Fault exposed in the piedmont of the Kepingtage fold-and-thrust belt. The depth of the main earthquake rupture was ~ 0–(16 ± 3) km, controlled by the NEE-oriented extrusion stress. The main rupture led to the dislocation of the horizontal slip layer in the Palaeozoic sedimentary cover of the Kepingtage fold-and-thrust belt. Calculations of static Coulomb stress changes indicated a reduced risk of future earthquakes in the Maidan Fault, while the potential rupture risk of the Wensu North Fault needs to be considered. The InSAR deformation field of the aftershocks reflected that the deformation field of the two strong 5.7-magnitude aftershocks was 15 km south of the mainshock. The aftershock's seismogenic fault was a thrust fault in the middle of the Wushi Basin. This was a branch fault of the main shock; i.e., a forward spreading fault developed at the front end under the continuous thrust of the Maidan Fault.